Essential Regulatory Requirements for Laboratory Weighing
Weighing is a crucial step in analytical procedures, making lab scales indispensable in QC labs. Explore this page to understand how the essential requirements for lab balances are described in different chapters of international pharmacopeias like USP <1251>, USP <41>, Eur.Ph. 2.1.7, JP 9.62, ChP 9032, FDA requirements for electronic records and data integrity as described in 21 CFR part 11 and general guidelines like the calibration guide no. 18 (EURAMET cg18) published by the association of European metrology institutes.
Learn about the essential requirements for electronic balances in QC labs, including good practices, international compliance, minimum weight and smallest net weight, and data integrity.
Introducing the Cubis® II for Connectivity & Compliance
Cubis® II by Sartorius ensures precise results, regulatory compliance, and seamless connectivity with modern IT environments.
Enhance your laboratory's efficiency and data integrity with Cubis® II's intelligent functions, comprehensive audit trails, and customizable workflows, designed to meet the demands of Lab 4.0.
Updated Requirements for Balances in the Pharmaceutical Industry
The pharmaceutical industry is undergoing significant changes in balance requirements, driven by international harmonization efforts. Major pharmacopoeias—USP, Ph.Eur., JP, and ChP—have revised their guidelines to ensure precise regulations. These updates highlight the importance of reliable balances in achieving accurate analytical results.
USP <41> vs USP <1251>
Compare USP <41> and USP <1251> to understand the differences between weighing performance requirements and balance qualification guidelines.
Topic | USP <41> : Weighing on an Analytical Balance | USP <1251> : Balance Qualification |
|---|---|---|
| Focus / Purpose | Defines performance requirements for accurate weighing. | Provides guidance on qualification, calibration and verification of balances. |
| Scope | Specifies how the balance must perform during weighing activities. | Specifies how the balance must be qualified to ensure it is fit for its intended use. |
| Key Requirements |
|
|
| Performance Checks | Requires accuracy and repeatability tests using calibrated weights. | Provides guidance on defining intervals and procedures for calibration and checks. |
| Minimum Weight | Clarifies how to determine minimum weight based on repeatability results. | Refers to minimum weight but focuses on ensuring qualification supports accurate minimum weight. |
| Environmental Conditions | Emphasizes environmental factors that affect weighing accuracy (temperature, drafts, vibration). | Emphasizes environmental controls during installation and qualification. |
| Safety Factor | Not addressed or required. | Introduces the safety factor concept (optional, not mandatory). |
| Traceability | Requires weights traceable to SI units. | Strengthens metrological traceability expectations. |
| Effective Date | Updated chapter effective February 2026. | Revised chapter aligned with modernization; effective February 2026. |
Current Revision Status and Regulatory Framework
- USP: The USP has revised its chapters on balances, with updates effective from February 2026. These revisions are enforced by the Federal Food, Drug, and Cosmetic Act (FDCA).
- Ph.Eur: Expected revisions to Chapter 2.1.7 will be published by late 2026, enforced by EU Directive 2001/83/EC and EU Regulation 2019/6.
- JP: New chapters on balances will be implemented by the end of 2025, under the Pharmaceutical and Medical Device Act (PMD Act).
- ChP: Introduced new guidelines in early 2025, enforced by the Drug Administration Law of the People's Republic of China.
Key Requirements for Compliant Laboratory Weighing
Explore the essential requirements that ensure accurate, reliable, and compliant weighing in laboratory environments, including environmental control, calibration practices, performance checks, minimum weight definitions, and support tools that enable consistent regulatory compliance.
All pharmacopoeias emphasize environmental control in balance operation:
- Temperature: Stable, avoiding direct sunlight.
- Humidity: 40% to 60% RH.
- Air Currents: Minimize drafts.
- Vibration: Use anti-vibration tables.
- Static Electricity: Use antistatic devices.
- Electromagnetic Fields: Avoid RF/magnetic sources.
- Cleanliness: Maintain a clean area.
Calibration ensures metrological traceability to the International System of Units (SI):
- USP: Emphasizes periodic calibration.
- Ph.Eur. and ChP: Similar requirements.
- JP: Provides background on traceability.
Performance checks focus on accuracy and repeatability:
Accuracy
- Sensitivity: Check using a weight >5% of the balance’s maximum capacity.
- Calibrated Weight: Use a weight with uncertainty <1/3 of the acceptance criterion.
Repeatability
- Weight: Use a weight ≤5% of the balance’s maximum capacity.
- Procedure: Zero balance, place weight, record indication, repeat 10 times.
Clarification of "minimum weight" and "smallest net weight":
- Smallest Net Weight (msnw): User-defined smallest sample quantity.
- Minimum Weight (mmin): Calculated from performance checks.
Sartorius offers recommendations and assets to support compliance:
- Environmental Conditions: Check and improve as necessary.
- Device Features: Utilize features like IsoCal function.
- Performance Checks: Define intervals based on risk analysis.
- Calibration: Define intervals and tolerances.
Supporting Assets
- White Paper Bundle: Guides on compliant weighing practices.
- Generic Operating Procedures: Harmonized procedures for performance checks.
- Service Certificates: Ensuring reliable measurement results.
Regulatory Landscape for Compliant Lab Weighing
United States Pharmacopeia <1251> - Weighing on an Analytical Balance
USP general chapter <1251> offers best practices for laboratory weighing, including selecting the right balance for accuracy, proper placement and installation, calibration and verification, routine testing and maintenance, correct weighing techniques, and documentation and traceability of procedures.
Download the Infographic for an optimal use of your lab balances in Pharma industry
United States Pharmacopeia <41> - Balances
USP general chapter <41> outlines stringent requirements for laboratory balances, focusing on accurate weighing, calibration, and adherence to standards for repeatability and accuracy, including the concept of the smallest net weight. This chapter ensures that balances used in pharmaceutical applications meet precise criteria to maintain the integrity of measurements.
European Pharmacopeia General Chapter 2.1.7 – Balances for Analytical Purposes
EP 2.1.7 provides comprehensive guidelines for the use and maintenance of analytical balances, covering principles of mass determination, installation considerations, and the use of appropriate weighing vessels. It emphasizes the importance of calibration, repeatability, sensitivity, and adherence to the minimum weight requirement in performance checks.
EURAMET Calibration Guide No. 18 – Guidelines on the calibration of Non-Automatic Weighing Instruments
The EURAMET cg-18 guide details the calibration of non-automatic weighing instruments to ensure consistent and recognized results across laboratories. It includes calibration elements, test loads, measurement methods, uncertainty, and certificate preparation, with appendices on air buoyancy, convection effects, and minimum weight. Calibration is done over to maintain high standards in mass measurement.
Download this white paper to learn about the calibration guideline, measurements carried out as part of the calibration process and Sartorius specifications
Japanese Pharmacopeia Chapter 9.62 - Measuring Instruments, Appliances
Chapter 9.62 of the Japanese Pharmacopoeia has been extensively revised and published in June 2024to include detailed requirements for the calibration, repeatability, and accuracy of balances, emphasizing the importance of the smallest net weight. It mandates that balances be calibrated to ensure traceability to the SI and that repeatability checks confirm the minimum weight is smaller than the smallest net weight. Additionally, the chapter requires periodic accuracy checks to ensure sensitivity errors are within acceptable limits.
Uniformity of dosage unit described in EP 2.9.40 - USP <905> - JP 6.02 and harmonized by ICH guidance Q4B annex 6
EP 2.9.40, USP <905>, and JP 6.02 describe the test for drug content uniformity in dosage units such as tablets and capsules in pharmaceutical or nutraceutical quality control. This test ensures that each individual unit of a drug product contains the intended amount of active ingredient within an acceptable range. Accurate weighing is crucial in these procedures, as it directly impacts the assessment of dosage uniformity, including criteria for acceptance based on statistical sampling and analysis.
Download the application highlight to learn how weight testing can be easily performed using the Cubis® II MCA balance and QApp tablet check.
Residue of ignition described in EP 2.4.14 - USP <281> - JP 2.44 and harmonized by ICH guidance Q4B annex 1
The residue on ignition - or sulfated ash - test described in EP 2.4.14, USP <281>, and JP 2.44 determines the amount of residual substance remaining after a sample is ignited, which is crucial for assessing the purity and quality of pharmaceutical substances. Accurate weighing by difference is essential in this procedure, as it is directly involved in the determination of the residue amount.
Download this informative application highlight to learn more about the role Cubis® II balances streamline the test procedure.
Loss on drying described in USP <731> - EP 2.2.32 - JP 2.41
The loss on drying (LOD) test, described in USP <731>, EP 2.2.32, and JP 2.41 measures the amount of volatile matter, such as water, in a sample. This test is crucial for determining the moisture content of pharmaceutical substances, which can affect their stability, efficacy, and shelf life. Accurate differential weighing is essential as it directly impacts the precise determination of the moisture content.
In the Cubis® II application, administrators can select USP or PhEur test procedures and choose the sample type—tablet or capsule. This determines how the software evaluates pass or fail based on weight differences. Download the application note to learn more.
Electronic records and data integrity as described in 21CFR Part 11, EU Annex 11 or ALCOA principle
21 CFR Part 11, EU Annex 11, and the ALCOA principles are essential for ensuring compliance in electronic data management within the pharmaceutical industry. These regulations outline Good Manufacturing Practice (GMP) protocols, including the use of electronic signatures, data integrity, and system validation, to ensure that electronic records are trustworthy and reliable.
Download the infographic for an overview of key terms and definitions, points of compliance, and ways to achieve quality control and data integrity.
Certified and accredited services for lab weighing instruments
Sartorius Services ensure lab balances meet GLP/GMP standards, providing audit security and comprehensive documentation. Our risk-based IQ/OQ qualification ensures compliance and peace of mind. Regular maintenance contracts enhance process safety, extend instrument life, and ensure reliable results. Calibration services guarantee accuracy, regulatory compliance, and traceability, with certificates meeting ISO/IEC 17025, USP, and European Pharmacopeia standards.
Ensuring Data Integrity: Connected Solutions
Data Integrity is a necessity in scientific research and pharmaceutical manufacturing. It is essential for reliable results, ensures compliance, product quality, and patient safety. In order to stay compliant, modern lab equipment is designed to simplify data integrity compliance by automation. Explore this infographic to understand the importance of data integrity, the FDA’s focus on data integrity violations, and ultimately Sartorius connected solutions that help ensure compliance.
Audit Preparedness with Cubis® II Balances
Many analytical techniques involve weighing steps, where errors can occur. These mistakes can have significant and cumulative effects, potentially leading to invalidation of release tests, cross-contamination, or high analytical uncertainties. Recognizing the importance of accurate weighing, pharmacopoeias provide guidance on planning, verification, and protocol.
This guide helps you understand how the Cubis® II balances secure your daily weighing reliability and back you up for internal or external audits.
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